Extract interface from membership.HostInfo

common/membership/hostinfo.go

@@ -24,41 +24,25 @@
 
 package membership
 
-// HostInfo is a type that contains the info about a temporal host
-type HostInfo struct {
-	addr   string // ip:port
-	labels map[string]string
+// HostInfo represents the host of a Temporal service.
+type HostInfo interface {
+	// Identity returns the unique identifier of the host.
+	// This may be the same as the address.
+	Identity() string
+	// GetAddress returns the IP address of the host.
+	GetAddress() string
 }
 
-// NewHostInfo creates a new HostInfo instance
-func NewHostInfo(addr string, labels map[string]string) *HostInfo {
-	if labels == nil {
-		labels = make(map[string]string)
-	}
-	return &HostInfo{
-		addr:   addr,
-		labels: labels,
-	}
-}
-
-// GetAddress returns the ip:port address
-func (hi *HostInfo) GetAddress() string {
-	return hi.addr
-}
+type hostAddress string
 
-// Identity implements ringpop's Membership interface
-func (hi *HostInfo) Identity() string {
-	// for now we just use the address as the identity
-	return hi.addr
+func (hi hostAddress) GetAddress() string {
+	return string(hi)
 }
 
-// Label implements ringpop's Membership interface
-func (hi *HostInfo) Label(key string) (value string, has bool) {
-	value, has = hi.labels[key]
-	return
+func (hi hostAddress) Identity() string {
+	return string(hi)
 }
 
-// SetLabel sets the label.
-func (hi *HostInfo) SetLabel(key string, value string) {
-	hi.labels[key] = value
+func NewHostInfoFromAddress(address string) HostInfo {
+	return hostAddress(address)
 }

common/membership/hostinfo_provider.go

@@ -37,7 +37,7 @@ var HostInfoProviderModule = fx.Options(
 
 type (
 	CachingHostInfoProvider struct {
-		hostInfo          *HostInfo
+		hostInfo          HostInfo
 		membershipMonitor Monitor
 	}
 )
@@ -57,7 +57,7 @@ func (hip *CachingHostInfoProvider) Start() error {
 	return nil
 }
 
-func (hip *CachingHostInfoProvider) HostInfo() *HostInfo {
+func (hip *CachingHostInfoProvider) HostInfo() HostInfo {
 	return hip.hostInfo
 }
 

common/membership/interfaces.go

@@ -52,22 +52,22 @@ type (
 
 	// ChangedEvent describes a change in membership
 	ChangedEvent struct {
-		HostsAdded   []*HostInfo
-		HostsUpdated []*HostInfo
-		HostsRemoved []*HostInfo
+		HostsAdded   []HostInfo
+		HostsUpdated []HostInfo
+		HostsRemoved []HostInfo
 	}
 
 	// Monitor provides membership information for all temporal services.
 	// It can be used to query which member host of a service is responsible for serving a given key.
 	Monitor interface {
 		common.Daemon
 
-		WhoAmI() (*HostInfo, error)
+		WhoAmI() (HostInfo, error)
 		// EvictSelf evicts this member from the membership ring. After this method is
 		// called, other members will discover that this node is no longer part of the
 		// ring. This primitive is useful to carry out graceful host shutdown during deployments.
 		EvictSelf() error
-		Lookup(service primitives.ServiceName, key string) (*HostInfo, error)
+		Lookup(service primitives.ServiceName, key string) (HostInfo, error)
 		GetResolver(service primitives.ServiceName) (ServiceResolver, error)
 		// AddListener adds a listener for this service.
 		// The listener will get notified on the given
@@ -93,7 +93,7 @@ type (
 	// ServiceResolver provides membership information for a specific temporal service.
 	// It can be used to resolve which member host is responsible for serving a given key.
 	ServiceResolver interface {
-		Lookup(key string) (*HostInfo, error)
+		Lookup(key string) (HostInfo, error)
 		// AddListener adds a listener which will get notified on the given
 		// channel, whenever membership changes.
 		// @name: The name for identifying the listener
@@ -104,13 +104,13 @@ type (
 		// MemberCount returns host count in hashring for any particular role
 		MemberCount() int
 		// Members returns all host addresses in hashring for any particular role
-		Members() []*HostInfo
+		Members() []HostInfo
 		// Requests to rebuild the hash ring
 		RequestRefresh()
 	}
 
 	HostInfoProvider interface {
 		Start() error
-		HostInfo() *HostInfo
+		HostInfo() HostInfo
 	}
 )

common/membership/ringpop_hostinfo.go

@@ -0,0 +1,63 @@
+// The MIT License
+//
+// Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
+//
+// Copyright (c) 2020 Uber Technologies, Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+package membership
+
+type ringpopHostInfo struct {
+	addr   string // ip:port
+	labels map[string]string
+}
+
+// newRingpopHostInfo creates a new *ringpopHostInfo instance
+func newRingpopHostInfo(addr string, labels map[string]string) *ringpopHostInfo {
+	if labels == nil {
+		labels = make(map[string]string)
+	}
+	return &ringpopHostInfo{
+		addr:   addr,
+		labels: labels,
+	}
+}
+
+// GetAddress returns the ip:port address
+func (hi *ringpopHostInfo) GetAddress() string {
+	return hi.addr
+}
+
+// Identity implements ringpop's Membership interface
+func (hi *ringpopHostInfo) Identity() string {
+	// for now we just use the address as the identity
+	return hi.addr
+}
+
+// Label implements ringpop's Membership interface
+func (hi *ringpopHostInfo) Label(key string) (value string, has bool) {
+	value, has = hi.labels[key]
+	return
+}
+
+// SetLabel sets the label.
+func (hi *ringpopHostInfo) SetLabel(key string, value string) {
+	hi.labels[key] = value
+}

common/membership/rpMonitor.go

@@ -341,7 +341,7 @@ func (rpo *ringpopMonitor) Stop() {
 // This is different from service address as we register ringpop handlers on a separate port.
 // For this reason we need to lookup the port for the service and replace ringpop port with service port before
 // returning HostInfo back.
-func (rpo *ringpopMonitor) WhoAmI() (*HostInfo, error) {
+func (rpo *ringpopMonitor) WhoAmI() (HostInfo, error) {
 	address, err := rpo.rp.WhoAmI()
 	if err != nil {
 		return nil, err
@@ -360,7 +360,7 @@ func (rpo *ringpopMonitor) WhoAmI() (*HostInfo, error) {
 	if err != nil {
 		return nil, err
 	}
-	return NewHostInfo(serviceAddress, labels.AsMap()), nil
+	return newRingpopHostInfo(serviceAddress, labels.AsMap()), nil
 }
 
 func (rpo *ringpopMonitor) EvictSelf() error {
@@ -375,7 +375,7 @@ func (rpo *ringpopMonitor) GetResolver(service primitives.ServiceName) (ServiceR
 	return ring, nil
 }
 
-func (rpo *ringpopMonitor) Lookup(service primitives.ServiceName, key string) (*HostInfo, error) {
+func (rpo *ringpopMonitor) Lookup(service primitives.ServiceName, key string) (HostInfo, error) {
 	ring, err := rpo.GetResolver(service)
 	if err != nil {
 		return nil, err

common/membership/rpMonitor_test.go

@@ -120,13 +120,13 @@ func (s *RpoSuite) testCompareMembers(curr []string, new []string, expectedDiff
 	if event != nil {
 		var diff []string
 		for _, a := range event.HostsAdded {
-			diff = append(diff, "+"+a.addr)
+			diff = append(diff, "+"+a.GetAddress())
 		}
 		for _, a := range event.HostsUpdated {
-			diff = append(diff, "~"+a.addr)
+			diff = append(diff, "~"+a.GetAddress())
 		}
 		for _, a := range event.HostsRemoved {
-			diff = append(diff, "-"+a.addr)
+			diff = append(diff, "-"+a.GetAddress())
 		}
 		s.ElementsMatch(expectedDiff, diff)
 	}

common/membership/rpServiceResolver.go

@@ -158,17 +158,15 @@ func (r *ringpopServiceResolver) RequestRefresh() {
 }
 
 // Lookup finds the host in the ring responsible for serving the given key
-func (r *ringpopServiceResolver) Lookup(
-	key string,
-) (*HostInfo, error) {
+func (r *ringpopServiceResolver) Lookup(key string) (HostInfo, error) {
 
 	addr, found := r.ring().Lookup(key)
 	if !found {
 		r.RequestRefresh()
 		return nil, ErrInsufficientHosts
 	}
 
-	return NewHostInfo(addr, r.getLabelsMap()), nil
+	return newRingpopHostInfo(addr, r.getLabelsMap()), nil
 }
 
 func (r *ringpopServiceResolver) AddListener(
@@ -204,10 +202,10 @@ func (r *ringpopServiceResolver) MemberCount() int {
 	return r.ring().ServerCount()
 }
 
-func (r *ringpopServiceResolver) Members() []*HostInfo {
-	var servers []*HostInfo
+func (r *ringpopServiceResolver) Members() []HostInfo {
+	var servers []HostInfo
 	for _, s := range r.ring().Servers() {
-		servers = append(servers, NewHostInfo(s, r.getLabelsMap()))
+		servers = append(servers, newRingpopHostInfo(s, r.getLabelsMap()))
 	}
 
 	return servers
@@ -274,7 +272,7 @@ func (r *ringpopServiceResolver) refreshNoLock() (*ChangedEvent, error) {
 
 	ring := newHashRing()
 	for _, addr := range addrs {
-		host := NewHostInfo(addr, r.getLabelsMap())
+		host := newRingpopHostInfo(addr, r.getLabelsMap())
 		ring.AddMembers(host)
 	}
 
@@ -373,13 +371,13 @@ func (r *ringpopServiceResolver) compareMembers(addrs []string) (map[string]stru
 	for _, addr := range addrs {
 		newMembersMap[addr] = struct{}{}
 		if _, ok := r.membersMap[addr]; !ok {
-			event.HostsAdded = append(event.HostsAdded, NewHostInfo(addr, r.getLabelsMap()))
+			event.HostsAdded = append(event.HostsAdded, newRingpopHostInfo(addr, r.getLabelsMap()))
 			changed = true
 		}
 	}
 	for addr := range r.membersMap {
 		if _, ok := newMembersMap[addr]; !ok {
-			event.HostsRemoved = append(event.HostsRemoved, NewHostInfo(addr, r.getLabelsMap()))
+			event.HostsRemoved = append(event.HostsRemoved, newRingpopHostInfo(addr, r.getLabelsMap()))
 			changed = true
 		}
 	}

common/membership/rp_cluster_test.go

@@ -98,7 +98,7 @@ func NewTestRingpopCluster(
 			logger.Error("Failed to build broadcast hostport", tag.Error(err))
 			return nil
 		}
-		cluster.hostInfoList[i] = HostInfo{addr: cluster.hostAddrs[i]}
+		cluster.hostInfoList[i] = newRingpopHostInfo(cluster.hostAddrs[i], nil)
 	}
 
 	// if seed node is already supplied, use it; if not, set it
@@ -209,9 +209,9 @@ func (c *TestRingpopCluster) GetHostAddrs() []string {
 // the given addr, if it exists
 func (c *TestRingpopCluster) FindHostByAddr(addr string) (HostInfo, bool) {
 	for _, hi := range c.hostInfoList {
-		if hi.addr == addr {
+		if hi.GetAddress() == addr {
 			return hi, true
 		}
 	}
-	return HostInfo{}, false
+	return nil, false
 }

common/resourcetest/resourceTest.go

@@ -117,7 +117,7 @@ const (
 	testHostName = "test_host"
 )
 
-var testHostInfo = membership.NewHostInfo(testHostName, nil)
+var testHostInfo = membership.NewHostInfoFromAddress(testHostName)
 
 // NewTest returns a new test resource instance
 func NewTest(
@@ -248,7 +248,7 @@ func (t *Test) GetHostName() string {
 }
 
 // GetHostInfo for testing
-func (t *Test) GetHostInfo() *membership.HostInfo {
+func (t *Test) GetHostInfo() membership.HostInfo {
 	return testHostInfo
 }